The field of the present invention is telecommunications systems and, more particularly, systems and methods for generating and transmitting key press status messages within telecommunications systems and/or networks.
Recently, substantial attention has been directed toward the field of digital telecommunications systems and, in particular, toward the development of digital wireless telecommunications systems. To obtain and transmit key press status information conventional telecommunications systems generally employ a microprocessor and associated firmware to continuously monitor a key pad grid to detect when a key on an associated key pad has been depressed. Upon detecting a key press, the microprocessor generates a key press status message and, in many instances, causes a dual tone multifrequency (DTMF) signal to be delivered to an associated coder/decoder (CODEC) circuit. The analog DTMF signal is then converted by the CODEC circuit to a digital signal for transmission within a frame of data to be transmitted over the communications network. The key press status information is provided by the microprocessor to a digital signal processing unit that arranges, for example, digital voice, status or control data, and sync data to be transmitted within each frame.
Those skilled in the art will appreciate that the provision of a microprocessor in a handset solely for the purpose of monitoring a key pad grid and generating status messages upon the detection of a key press adds substantially to the cost of a handset. In addition, the provision of such a processor in cellular or wireless handsets adds substantially to the mass of circuitry provided in the handset.
Thus, it is believed that those skilled in the art would find a system and method for monitoring and detecting key press status without the use of a dedicated microprocessor to be quite useful.